How do i repair sump pumps?

[mickfoely]

Mine died tonight, two pumps don't ever run at all, one pump powers up and hums, but does not pump.

Any sites on the net that will tell me how to repair them?

About how much does it cost to have someone fix them? Would it be better to buy new?

[LazyPup]

A sump pump is nearly a foolproof piece of equipment. It is simply an electric motor mounted on the top of a tubular shaft with a long drive shaft down to a centrifigal pump impellor and a float switch to control it.

Due to the cost and difficulty in locating parts most fractional horsepower sump pumps used in residential service are seldom repaired, However, there are a couple things you should check before condemning it for a new one.

MAKE SURE THE PUMP IS UNPLUGGED BEFORE SEVICING.

1. Check the intake screen on the bottom of the pump housing to insure it is not plugged up with debris.

2. Remove the bottom cover on the pump housing and check to see if debris is jamming the impellor. The impellor should turn rather freely with only a light resistance. If it is difficult to turn by hand either it is jammed with debris or the bearings have seized.

3.Check the backflow preventer on the discharge line to insure it is not stuck closed.

4.Check the start capacitor. Remove the metal cover to access the capacitor. A WORD OF CAUTION HERE: check again to be sure the motor is unplugged- capacitors can store a charge for days after they are unplugged so be careful not to touch the electrical contacts.

Once you have accessed the capacitor you must discharge it by touching a screwdriver across both electrical terminals.

To test the capacitor you will need an analog type ohm meter (needle type, not a digital). Set your ohm meter on the highest resistance scale and touch one probe to each of the terminals on the capacitor. If the indicator needle on your ohm meter rises quickly then falls back to zero, reverse the test probes and try again. The needle should rise quickly and fall back again. If so, the capacitor is ok. If the needle does not move the capacitor is "Open" and if the needle goes to up and stays up the capacitor is "shorted" If the capacitor is either open or shorted you will need to change the capacitor.

If you have not located the problem by this point, the problem will most likely be an internal problem in the motor. Normally it is more cost effective to consider replacing the pump assembly.



I persoanlly prefer the submersible type sump pumps for a number of reasons:

1. the motor is submersed in water and it cools better.

2. Less noise

3. The motor and controls are completely in the sump which eliminates the common problem of a control arm jamming against the sump cover and preventing the pump from coming on, or keeping the pump on after the sump is dry and overheating the motor.

[mickfoely]

Thanks for the advice. I opened up one of my submersible sump pumps and found that it contains a fine oil, i spilled quite a bit of that. Should i replace this oil with something? Or is it just a byproduct from the water getting inside?

[LazyPup]

On the underside of a submersible sump pump there is an intake screen that can be removed for cleaning. Other than that screen there are no user servicable parts or components.

under no circumstances should the waer tight motor housing assembly, the water tight electrical connector or the float switch assembly be disassembled.

Opening the motor housing will violate the integrity of the water tight seals and will result in a serious risk of electrical failure and potential electrical shock hazard.

[mickfoely]

What was that oil inside?

[LazyPup]

Having an insatiable curiosity about all things mechanical on more than one occassion I have taken the liberty to open up burned out submersible sump pumps just to view the interior design characteristics.

From my experience most residential grade submersibles have a plastic or plastic coated steel housing that is either glued or fusion heat sealed and required physically cutting the housing to get it open. Inside I typically found a fractional horsepower motor with a centrifical start switch. Both the upper and lower shaft bearings were lifetime lubed dry bearings pressed on the shaft with a pressed on water tight seal on the lower bearing where the shaft passes through the housing into the impellor chamber. In no case did I find any free standing oil in the motor housings.

One of the pumps I took apart had a stainless steel housing which was connected to the impellor housing base by means of bolts. Once the bolts were removed it required considerable force to pry the impellor secton away from the stainless steel motor housing and I found the steel motor housing was sealed to the base by means of a double neoprene gasket system that appeared to have a silicone sealant applied to each layer of neoprene. Here again, it was a dry type motor with no oil present.

Based upon the typical design of submersible sump pumps there is an extremely high likelihood that they would occassionally be laid on their sides therefore, in my opinion, if there was oil present in the motor housing it would need to be an electrically non-conductive type oil such as found in an Air Conditioner or Refrigeration sealed hermetic compressor. The oil would further need to be specially formulated to insure it would not wash the varnish insulation off the wire used to make the motor windings. In short, it would need to be a special oil which would probably be very difficult to identify or purchase.

If you pulled the intake screen off the bottom of the pump to expose the impellor section you may have found a residual liquid that was yellowish-white, gray or black and had the consistancy of a light grade of oil. That is a very common gunk that forms in the impellor housings of sump pumps as a result of dirt, oils, soaps or other residues that may be present in the bottom of sumps. i would suspect that it may also result from some bacterial action as there is always a small amount of water present in the bottom of a sump pit that will stagnate. In fact, it is not uncommon to see a golden sheen on the top of the standing water that has the same appearance as when gasoline or oil is spilled on water.

You should be able to easily clean the impellor and impellor housing by first spraying with a good household spray cleaner, then hose out the housing with a garden hose.

[HayZee518]

That oil is the same low viscosity oil uses in air conditioning compressors It is pretty much void of moisture and forms the cooling and insulation of the motor.